Caveman
Mordecai and Rigby are going camping in a cave that is in the park. They begin playing video games and other things until going to sleep. An ice block near them unfreezes and inside is a Caveman. It awakens M&R who are scared at first until they find him cool. The next day, Benson finds him and tells Mordecai and Rigby to get rid of him. M&R beg him not to, and Benson tells them that they have a week to civilize him. M&R get help from Skips, Pops, Muscle Man and Hi Fives and they soon civilize him, and learn that his name is Greg. He wishes for love and he, Mordecai and Rigby go back to the cave and find his love, Dianne. He unfreezes her and they talk about "sorting things out". She tells Greg that she doesn't know him anymore and she leaves, to unfreeze the tribe. M,R&G go after her until they see that already, the tribe is attacking people and destroying the Park. Greg then gets an idea of getting meat and luring them into the Meat Locker. Their plan works but Greg stays behind so that he can stay with Dianne until he melts again. His tribe freezes and he and Dianne kiss and hold each other while Greg holds the thumbs up sign at M&R and freezes. Mordecai and Rigby are filled with sadness and meet Benson at the top, who tells them that he was wrong about Greg. He sobs while telling them that they must clean up the mess that the cavemen made or their fired. Rigby then asks Mordecai that after losing Greg, that they should get a third best friend, but Mordecai disagrees.
Characters
Main
Mordecai
Rigby
Greg
Minor
Dianne
Benson
Skips
Pops
Muscle Man
High Five Ghost
Cavemen
Mordecai
Rigby
Greg
Minor
Dianne
Benson
Skips
Pops
Muscle Man
High Five Ghost
Cavemen
Greg growling at Mordecai and Rigby M&R scared of Greg M&R teaching Greg some laws